Factors affecting the persistence of traditional agricultural landscapes in Slovakia during the collectivization of agriculture

Collectivization of agriculture (1950s–1970s) was one of the most important periods in landscape development in Slovakia. Traditionally managed agricultural landscapes, that covered more than half of the Slovak territory, were transformed into large-scale fields and only fragments of traditional agricultural landscapes survived. We mapped the remaining traditional agricultural landscapes using aerial photos and historical maps. We then statistically analyzed the various geographical factors and their influence on the transformation process of traditional and collectivized fields, i.e., slope steepness, soil fertility, distance from settlements and isolation from regional capital cities. The comparison was performed using classification tree analysis. We constructed a set of decision rules that explain why fields were managed traditionally or collectivized. Our findings show that traditional agricultural fields were more likely to persist on steep terrain, less fertile soils, and on locations that were closer to the settlements, but more isolated from the regional capital cities. Steepness played the most important role: small-scale fields located on steep areas were not accessible to heavy machinery and therefore, frequently survived the collectivization. We show that the selected geographical factors are good explanatory variables for the collectivization of arable fields and orchards. For vineyards and grasslands, however, the explanatory power of the selected geographical factors is lower, and we suspect that other factors, not depicted in the analysis play an important role.     

Spectral sensitivity in the photodegradation of fir wood (Abies alba Mill.) surfaces: colour changes in natural weathering

Activation spectra of wood under natural irradiation were investigated in detail in this work. The main purpose was to study colour changes on the wood surface over time and into the depth during natural light exposure and thus to further contribute to the optimization of surface-protecting treatments. In a natural weathering test, three 80-μm-thick strips of fir wood forming the surface layer of a wood composite were exposed to light under a series of glass cut-off filters. Samples were withdrawn at intervals and tested for colour changes. Identification of the most detrimental wavebands of light causing photodegradation was performed based on recorded colour changes. With chronological development of exposure, the colour changes shifted ever deeper into the surface and further into the visible region of the spectrum. A relatively narrow waveband from 360 to 435 nm was identified in the activation spectra to be the most active band, causing the greatest proportion of recorded colour changes. However, also visible light of wavelengths up to 515 nm significantly contributed to colour changes of the surface layers.     

Evaluation of mulched drip irrigation for cotton in arid Northwest China

Field experiments were conducted in arid Southern Xinjiang, Northwest China, for 3 years to evaluate sustainable irrigation regimes for cotton. The experiments involved mulched drip irrigation during the growing season and flood irrigation afterward. The drip irrigation experiments included control experiments, experiments with deficit irrigation during one crop growth stage, and alternative irrigation schemes in which freshwater was used during one growth stage and relatively saline water in the others. The average cotton yield over 3 years varied between 3,575 and 5,095 kg/ha, and the irrigation water productivity between 0.91 and 1.16 kg/m³. Crop sensitivities to water stress during the different growth stages ranged from early flowering-belling (most sensitive) > seedling > budding > late flowering-belling (least sensitive), while sensitivities to salt stress ranged from late flowering-belling > budding > seedling > early flowering-belling. Although mulched drip irrigation during the growing season caused an increase in salinity in the root zone, flood irrigation after harvesting leached the accumulated salts to below background levels. Numerical simulations, based on the 3-year experiments and extended by another 20 years, suggest that mulched drip irrigation using alternatively fresh and brackish water during the growing season and flood irrigation with freshwater after harvesting is a sustainable irrigation practice that should not lead to soil salinization.     

Meiosis and pollen grain viability in Helianthus mollis,Helianthus salicifolius,Helianthus maximiliani and their F1 hybrids with cultivated sunflower

Three diploid perennial sunflower species are useful for variety improvement: Helianthus mollis, because of sessile leaves, H. salicifolius, because of a high oil concentration, and H. maximiliani, a potential source of resistance to Sclerotinia sclerotiorum. The crossability of these species to cultivated sunflower was examined.Hybrids were obtained from eight combinations, with 3–15 F₁ plants per combination. The F₁'s exhibited the dominant phenotype of the wild species. Pollen viability varied between 32.1 and 69.9%. Meiosis was irregular in the F₁ hybrids. At diakinesis, bivalents (62.7–97.9% of meiocytes), univalents (0–31.23%), and multivalents (3.84–7.68%) were detected. At anaphase I, chromosome bridges were detected in 6.77 to 11.44% of meiocytes. Fast chromosomes in metaphase I, and lagging chromosomes in anaphase I and telophase II were evidenced in a high percentage of meiocytes.     

Characterization of isozyme variation in walnut(Juglans regia L.)

Summary Four leaf enzymes malate dehydrogenase (MDH), 6-phosphogluconate dehydrogenase (6PGD), peroxidase (PX) and aspartate aminotransferase (AAT) of 17 walnut cultivars and two pollen enzymes malate dehydrogenase (MDH) and 6-phosphogluconate dehydrogenase (6PGD) of 15 walnut cultivars were analysed using horizontal starch gel electrophoresis. Walnut cultivars of different origin exhibited different numbers of electrophoretic bands and also different relative mobility. Different activity levels and phenotypic groups were detected in studied enzyme systems. Pollen enzymes revealed higher variability than enzymes extracted from the leaves. 15 walnut cultivars were classified into 10 malate dehydrogenase phenotypic groups and 14 6-phosphogluconate dehydrogenase phenotypic groups based on pollen analyses. 17 cultivars were classified into 9 peroxidase phenotypic groups and 7 6-phosphogluconate dehydrogenase phenotypic groups based on analyses of leaves. All of the 15 walnut cultivars could be identified and distinguished with electrophoretic analyses of MDH and 6PGD from the pollen while only 10 cultivars were distinguishable with analyses of 6PGD and PRX from the leaves. No variability useful for cultivar identification was observed in MDH and AAT from the leaves.     

The sensitivity of water extractable soil organic carbon fractions to land use in three soil types

Soil organic carbon (SOC) has a high impact on the sustainability of ecosystems, global environmental processes, soil quality and agriculture. Long-term tillage usually leads to SOC depletion. The purpose of this study was to determine the impact of different land uses on water extractable organic carbon (WEOC) fractions and to evaluate the interaction between the WEOC fractions and other soil properties. Using an extraction procedure at 20°C and 80°C, two fractions were obtained: a cold water extractable organic carbon (CWEOC) and a hot water extractable organic carbon (HWEOC). The results suggest that there is a significant impact from different land uses on WEOC. A lower relative contribution of WEOC in SOC and a lower concentration of labile WEOC fractions are contained in arable soil compared to forestlands. Chernozem soil was characterized by a lower relative contribution of WEOC to the SOC and thus higher SOC stability in contrast to Solonetz and Vertisol soils. Both CWEOC and HWEOC are highly associated with SOC in the silt and clay fraction (<53 µm) and were slightly associated with SOC in the macroaggregate classes. The WEOC fractions were highly and positively correlated with the SOC and mean weight diameter.     

Effects of aluminum on mineral content of mycorrhizal fungi in vitro

The influence of Al³⁺ on the mineral content of mycorrhizal fungi was studied in vitro. Amanita muscaria (L. ex Fr.) Pers. ex Hooker whose growth is reduced and Lactarius piperatus (L. ex Fr.) S.F. Gray whose growth is stimulated by Al³⁺ where chosen for the experiments. 0, 0.1, 1, and 10mM A³⁺ were added as Al₂(SO₄)₃ · 18H₂O to modified M-40 medium. Al³⁺ drastically affected the mineral contents of the mycelia of both fungi: the Al, Ca, and Na contents increased while P, Mg, and K decreased with the increasing Al³⁺ concentrations in the media. On the other hand, some important differences between the two mycelia were detected. In the mycelia of Lacterius piperatus grown on the control media, there was about twice as much Ca content and a three times lower P content than in the Amanita muscaria mycelia. The Al³⁺ content in the mycelia of Lactarius piperatus grown on 10mM Al³⁺ was six times higher than in Amanita muscaria at the same concentration.     

Genotyping of Bacillus anthracis Isolated from Croatia and Bosnia and Herzegovina

Anthrax is a serious disease caused by Bacillus anthracis. Humans can become infected by handling products from infected animals, by breathing spores and rarely by eating undercooked meat from infected animals. The genome of B. anthracis is highly monomorphic and thus shows very low DNA sequence variation. We analysed the molecular characteristics of 12 B. anthracis isolates from outbreaks in Croatia and Bosnia and Herzegovina, which have occurred during the past 10 years along with two vaccine strains. Genotyping system based on variable‐number tandem repeat analysis at six loci revealed that six isolates belong to genotype from the A1.a cluster whilst six isolates relate to the B2 cluster, compared to 89 previously described genotypes. The distribution of two evolutionarily distant clusters suggests an introduction of B. anthracis to this area in at least two separate events.     

Serological Evidence for Borrelia burgdorferi Infection Associated with Clinical Signs in Dairy Cattle in Slovakia

In the course of epizootological research on Lyme borreliosis in domestic and farm animals, the serological evidence for the occurrence of this zoonosis in cattle was screened. An ELISA showed that 25.2% of cattle from seven geographical areas in Slovakia were positive for anti-Borrelia IgG antibodies. In particular localities, the seroprevalence ranged from 0.6% to 34.3%. Of 33 cases with clinical signs, 20 ELISA-positive samples were also confirmed in Western blots. The most frequent clinical signs were lameness and swollen joints, but most of the cases were asymptomatic. The occurrence of Borrelia burgdorferi antibodies and suspected clinical signs in cattle of Slovak regions indicates that veterinarians should pay attention to this disease in their clinical practice and include it within the differential diagnosis.